Improvements in or relating to window blinds,especially for aircraft passenger cabins

ABSTRACT

A window blind, especially for aircraft, consists of cross slats connected edge to edge by interwoven tapes, with spring strips bonded along the longitudinal side margins of the blind, these blind side margins being constrained to run in channelled guide rails. The spring strips have a naturally coiled configuration so that, where the blind leaves the guide rails at one end and enters a blind box, it is caused to roll up by the springs.

[ 1 Oct. 22, 1974 ilnited States Patent Jones l [56] References Cited I UNITED STATES PATENTS 2,584,369 2/1952 Renton 160/314 [75] Inventor: David Walter Jones, Shotton, Wales Hawker Siddeley Aviation Limited,

73 A Primary Examiner l. Karl Bell sslgnee' Attorney, Agent, or Firm-Rose & Edell Kingston upon Thames, Surrey, England [57] ABSTRACT A window blind, especially for aircraft, consists of [22] Filed: Feb. 2, 1973 [21] Appl. No.: 329,163

cross slats connected edge to edge by interwoven tapes, with spring strips bonded along the longitudinal [30] Foreign Application Priority Data side margins of the blind, these blind side margins Feb. 8, 1972 being constrained to run in channelled guide rails. The spring strips have a naturally coiled configuration so Great Britain 5887/72 de mm y mb m u 1 m a FAQ r e U M aw uw F u g E .m [S W .1 r t .1 D km 4 m m hd h .m C mm 1 a e an how w t .m 3mm was 28 2 4mWM4 M 3 6%38 l 6 ,MZZ 3 3!? 3"! H O "2 6 n m H 3 m u 2 n! 2 a". O mmm m mnm WWN H w3 mm 3 L C 0 wm k UrmF m m 555 WINDOW BLINDS, ESPECIALLY FOR AIRCRAFT PASSENGER CABINS This invention relates to blinds, more particularly for the windows or ports of vehicles and especially window blinds for aircraft passenger cabins.

It is an object of the invention to achieve a window blind which is both lightweight in construction and reliable in service.

One well know type of window blind is the roller blind, mounted with the roller axis horizontal at the top of the window aperture and comprising, within the roller, a torsion spring and ratchet mechanism. The action of closing, i.e. lowering, the blind loads the spring, which will then automatically induce the blind to open when released. The blind is held at'its fully closed or any intermediate position by the ratchet action. Although this device is satisfactory and reliable, the complexity of the roller assembly can lead to an undesirable weight penalty when installed on a passenger aircraft having a multiplicity of cabin windows.

The weight problem has hitherto been overcome by eliminating the roller assembly andmanufacturing the blind from Levolor (proprietary brand name) material. This consists of horizontal aluminium slats held together in edge-on abutment by interwoven glass-fibrereinforced plastics ribbons. The "blind is horizontally suspended from within a storage box at thetop of the window aperture. The vertical edges of the blind are covered with polytetrafiuorethylene tape and are retained by, and slide within, aluminium guide rails situated at each side of the window so that when the blind is pulled down to its fully closed or any desired intermediate position the slats are held in edge-on alignment to form a suitable light-excluding surface. Because there is no torsion spring assistance it is necessary to lift the blind manually and the retention of the slats in the guide rails ensures that they are maintained in alignment until the upper extremity of the guides is reached. At this point the slats are free to fold until the blind is completely within the storage box.

Although this is generally satisfactory there is the disadvantage that, in regular use, the repeated folding of the slats can lead to eventual breakdown of the PTFE tape at the edges of the slats. This tape, in turn, can peel off causing a deterioration in the blind action. Apart from the inconvenience to passengers and the presentation of an unsightly appearance, aircraft window blinds are normally contained within decorative trim panels and it is desirable that these should not be removed for such minor maintenance work.

According to the present invention, there is provided a blind for a window or port, especially of a vehicle, comprising numerous cross slats connected edge to edge by interwoven longitudinal tapes or ribbons, with a lightweight spring strip bonded along each longitudinal slide margin of the blind thereby further connecting the slats, and wherein said side margins including the spring strips are constrained to run in channels of side guide rails, the springs being covered with an antifriction material, such as polytetrafluor'ethylene, and the spring strips have a naturally coiled configuration such that where the blind runs out of the guide rails at one end it is caused to roll up by the springs.

The springs ensure that the blind, when raised, is retained in its storage box in neatly coiled form so that there is no significant folding of the slats. In fact, the

coiling will ensure substantially equal distribution :of relative slat movement, whereas with the previous arrangement the blind could very well fold at the same slat or slats on each occasion thereby accelerating breakdown. When the blind is lowered its margins continue to be retained by and slide within the side guide rails together with the extending springs which then uncoil, thus departing from their natural coiled configuration. But if constant-rate springs are used for this purpose, lowering of the blind does not set up a substantial load in the springs, and the blind can be maintained in any desired position by means of friction pads located in each rail.

An arrangement in accordance with the invention will now be described by way of example and with'reference to the accompanying drawings, in which:

FIG. 1 is a view of an aircraft cabin windowlooking outboard and from one half of which the decorative trim panel has been removed to clarify the assembly,

FIG. 2 is a vertical section taken through the assembly,

FIG. 3 is a typical part section taken through one side of the window assembly, and

FIG. 4 is a typical section through a guide rail.

In the drawings, an aircraft cabin window opening '1 has superimposed upon it, and symmetrical about the window vertical centre line, a window blind assembly 2. This blind assembly 2 comprises a formed surrounding framework 3 having parallel substantially vertical sides to which are attached extruded aluminium guides 4. The upper horizontal edge of the framework 3 is formed to provide a blind storage box 5 above the window aperture 1. The aluminium guides 4 extend'above and below the window opening, the upper ends in particular just encroaching into the blind storage box 35. The blind itself comprises horizontal aluminium slats '6 held in edge-on abutment by interwoven ribbons 7 of glass-fibre-reinforced plastics material. Bonded at the outboard blind face along the vertical edge margins of the blind, and thereby joining the slats at these edges, are two lightweight naturally coiled constant rate springs 8 covered, for anti-friction purposes, with PTFE tape.

When not in use, the coil springs 8 maintain the blind in neatly coiled form within the blind box 5. Retention of the blind within the blind box is by means of two arcuate spring brackets 9 located one near to each end of the blind box and in which the opposite ends of the coiled portion 15 of the blind rest; there is no roller, spindle or other pivot. The vertical edges of the blind, complete with the attached springs 8, slide within channels 14 in the guide rails 4, the blind being lowered or raised by means of a grip handle 10. The blind may be fully lowered or left at any intermediate position. Any slight tendency on the part of the springs to'coil the blind is resisted by anti-friction pads 11 contained within the guide channels of the rails 4 and comprising, in this example, strips of laminated fabric sheet bonded to a polyurethane foam. After final installation in the aircraft the blind assembly is enclosed by a decorative trim panel 12.

Although described for use in aircraft, the invention is equally applicable wherever such window blinds can be conveniently employed.

I claim:

1. A roller-less blind assembly for a vehicle window, comprising a flexible blind made up of numerous cross slats connected edge to edge by interwoven longitudinal tapes, with a lightweight spring strip bonded along each longitudinal side margin of said blind thereby further connecting the slats, antifriction material, such as polytetrafluorethylene, covering said spring strips, side guide rails having channels within which the blind side margins including said spring strips are constrained to slide, said spring strips having a naturally coiled configuration such that where the blind runs out of the side guide rails at one end it is caused to roll up by the springs, and a blind box at said one end to receive said rolled up portion of the blind, with arcuate resilient brackets in said blind box encircling said rolled-up por- ,tion at opposite ends thereof, to retain said rolled-up tion of extension to which it is manually adjusted. 

1. A roller-less blind assembly for a vehicle window, comprising a flexible blind made up of numerous cross slats connected edge to edge by interwoven longitudinal tapes, with a lightweight spring strip bonded along each longitudinal side margin of said blind thereby further connecting the slats, antifriction material, such as polyTetrafluorethylene, covering said spring strips, side guide rails having channels within which the blind side margins including said spring strips are constrained to slide, said spring strips having a naturally coiled configuration such that where the blind runs out of the side guide rails at one end it is caused to roll up by the springs, and a blind box at said one end to receive said rolled up portion of the blind, with arcuate resilient brackets in said blind box encircling said rolled-up portion at opposite ends thereof, to retain said rolled-up portion in predetermined position in said blind box without the provision of a blind roller, and wherein said springs have a constant spring rate and friction pads are provided in said guide rails to act on said blind side margins such that the blind remains stably in any position of extension to which it is manually adjusted. 